Dental implant systems are widely used for replacing damaged or lost natural teeth. In such systems, a dental fixture is placed in the jawbone of a patient in order to replace the natural tooth root. An abutment structure comprising one or several parts may then be attached to the fixture in order to build up a core for the part of the prosthetic tooth protruding from the bone tissue, through the soft gingival tissue and into the mouth of the patient. On said abutment, the prosthesis or crown may finally be seated.
The final prosthesis should be sized and configured so as to naturally fit with the remaining teeth of the patient, both for functionality and aesthetics. To this end a dental technician may try out a proper prosthesis for the individual patient, using a model of the jaw of the patient, said model including the fixture. The dental technician may also digitally work out a proper prosthesis based on a digital model of the jaw of the patient either with a fixture already installed or prior to such installation. The dental technician may also modify a pre-fabricated abutment to match the contour of the soft gingival tissue.
There are various fixture configurations. For instance, a fixture may have a flat topped coronal head portion, which may be installed in any rotational position relative to the jawbone. Another type of fixture configuration is a fixture having a sloped coronal end portion, such as disclosed in U.S. Pat. No. 6,655,961, in which the length of the fixture is greater on the lingual side than on the buccal side in order to match the contour of the jawbone.
Similarly, to the above described fixture/jawbone-interface, for a superstructure, such as an abutment, there may be an abutment/fixture-interface in which the abutment should only be positioned in one way relative to the fixture, e.g. an abutment having a sloped portion matching the sloped head portion of a fixture. This is one type of asymmetrical superstructure, in which the asymmetrical feature should be positioned in a desired rotational relationship to either or both of the fixture and the jawbone with surrounding teeth. Thus, with regard to these interfaces, it would be desirable to ensure that the dentist connects the superstructure with a correct rotational orientation relative to certain fixtures or jawbone features. Also for patient-specific or customized superstructures, such as a customized abutment, such superstructure may often be made with a certain intended rotational orientation relative to the fixture and surrounding contours. Thus, also in these cases it would be desirable to ensure that the dentist connects the superstructure with a correct rotational orientation relative to the fixture and other features in the oral cavity.
When making an abutment and a prosthetic tooth, the dental technician has thus taken the contours and locations of surrounding tissue and adjacent teeth into account. A system used at present time to manoeuvre the rotational position of asymmetrical superstructures is to provide a two-part abutment having a centrally positioned threaded screw, which mates with an internally threaded bore of the fixture, and a sleeve which is given the asymmetrical patient specific features at its coronal end which are needed to be a suitable basis for the prosthetic tooth. The sleeve may be rotated into the correct position in a seating of the internal bore of the fixture and be fixed therein by the screw. The seating in the fixture and the apical end of the sleeve of the abutment are axially symmetrical to ensure that a correct final position may be achieved. The correct positioning is this way depending on the dentist's ability to visually verify the result.
The dentist receives the abutment and prosthetic tooth either as one integral unit or as separate parts to be assembled in the oral cavity of the patient. Often, the dentist who receives the abutment and the prosthetic tooth should understand how the abutment should be rotationally oriented relative to the fixture in order to obtain the alignment as intended by the dental technician. Nevertheless, it may sometimes be difficult for the dentist to see which is the correct orientation and, of course, there may be a risk of the dentist simply overlooking or ignoring the correct rotational orientation of the abutment relative to the fixture.
There have been proposed different solutions which only allow the abutment to be placed in a single rotational orientation relative to the fixture. Nevertheless, dentists may still experience difficulties in finding the correct orientation, and may have to rotate the abutment for a while before it falls into place.
An object of the invention is to enable the dentists to find a desired rotational orientation of a dental component, such as an abutment, relative to a fixture more easily than what is offered by the currently available solutions.
These and other objectives, which will become apparent in the following, are achieved by the dental component and the dental implant as defined in the accompanied claims.